Scientists expect evidence of past life will be found on Mars

Mars probably harboured life in the past and may do so today

Mars probably harboured life in the past and may do so today. New satellites flying to the "Red Planet" over the next decade should be able to prove this view, according to a planetary research specialist.

The Irish co-ordinator of the International Planetary Society, Kevin Nolan, last night told an audience in Dublin about the latest research findings from Mars. In particular, his talk focused on the search for signs of past or present life hidden in the Martian landscape.

Mr Nolan's talk at the Bank of Ireland Arts Centre was part of Science Week Ireland, which finishes this Sunday. A lecturer in physics at IT Tallaght, he explained why scientists are so interested in the "Red Planet".

"Mars was a very active planet in its past. In particular, water played a very important role. There was also volcanic and seismic activity, and Mars must have looked much like early Earth. It can tell us a lot about life on early Earth. Mars was cooling down as life emerged on Earth.

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"The kind of activity is quite similar. I believe Mars will tell us a lot about what happened here."

The current consensus among most planetary scientists is that signs of past life will be found. "I am confident they will find evidence of past life. The feeling is that where you have strong surface activity and water, you will have prebiotic chemicals or even life."

There are signs that Mars even as it is today might provide a refuge for microbial life. "What Mars Express [the satellite] has found is Mars is still quite active and goes through a form of climate change." Atmospheric moisture levels occasionally spike to 100 times the average level, leading scientists to speculate that water exchange could allow microbes to persist. "They think there may be microbial life in niche areas," he said.

We won't have to wait too long for this to be proven one way or the other, he added. Nasa and the European Space Agency have agreed to co-ordinate their Mars exploration programmes.

"Over the next 10 years there will be a number of biological rovers and landers heading for Mars to look for evidence of ancient life or even current life.

"The assumption is that by 2012 we will have sent three biological rovers and by 2016 we will have sent a sample return mission," Mr Nolan said.

Dick Ahlstrom

Dick Ahlstrom

Dick Ahlstrom, a contributor to The Irish Times, is the newspaper's former Science Editor.